Tube-expander.



NITED STATE-S P TENT OFFICE.

OHARLES VANDELEUR BURTON, OF LONDON, ENGLAND.

TUBE-EXPANDER.

SPECIFICATION forming part Of Letters Patent NO. 677,930, dated July 9, 1901. Application filed December 4, 1900- Serial No. 38,693. (No model.)

T0 at whom it may concern: I

Be it known that I, CHARLES VANDELEU BURTON, a subject of the Queen of England, residing at London, England, have invented certain new and useful Improvements in Tube-Expanders, (for which application has been made in Great Britain, No. 19,529, dated October 31, 1900,) of which the following is a specification.

This invention relates to improved apparatus forexpanding hollow bodies so as to make a permanent change in their transverse dimensions.

The apparatus consists of a mandrel extending through a hole in a plate or bolster, a body or frame, and a slider or plunger, the mandrel and bolster being attached one'to the body and the other to the slider. The mandrel has a shouldered head, andmeans areprovided for producing relative displacement of the body and slider, thus forcing the mandrel back so that its shouldered head approaches the bolster. This shouldered head fits more or less closely in the hollow body to' be expanded, and in the annular space af-L forded between the shank of the mandrel and the bore of the hollow body is placed a bushing of a material which is capable of altering its shape under pressure. By forcing the shouldered portion of the mandrel toward the plate or bolster the bushing will be compressed axially and expanded radially, thus.

expanding the tubular ,body as desired.

The invention will now be fully described in connection with the accompanying drawings, of which- Figures 1, 2, 3, 4t, and 5 represent a convenient form of mandrel and bolster as applied to the expanding of a tube-say in the tube-plate of a boiler-the body and slider and the operative means being omitted. Fig. 6 is a plan, mainly in section, part in elevation, of a form of apparatus for operating the mandrel by fluid-pressure, the admissiontube for the motor fluid and the yalve-operating spindle being omitted. Fig. 7 is a section on thelinea; 0c of Fig.6. Fig. 8 is a section on the line y y of Fig. 6, but with the fluid admission and discharge and valveoperating spindle in position. Fig. 9' is an end view of the valve-chest detached. Fig.

10 is a longitudinal section of an apparatus in which the mandrel is operated mechanically.

Like letters indicate like parts in all the figures. V

A is the shank of the mandrel, which forms a working fit with a hole in a head plate or bolster B. Preferablythe hole is tapered,as shown in the figures, so as to be quite free of the mandrel, except at one point, Where it forms a,working' fit. The face of the bolster which is presented to the work may be flat or it may be curved or beveled. The man drel-shank is provided with a head A of a larger diameter than the shank, the junction of the head and shank being preferably eased off by a curved or beveled shoulder A The head A fits more or less closely in the bore of the body to be expanded. The mandrel is extended beyond the bolster, the distance between the head A and the face of the bolster depending on the length of the portion of the tubular body to be expanded, and this portion of the mandrel-shank is fitted with a bushing E of outside diameter about equal tothat of the mandrel-head A and formed of a deformable material-that is to say, one capable of readily altering its shape under stress. A body, which may be a fluid pressure cylinder or merely a frame, and a slider,'which may be the piston of the cylinder or a bridge-piece operated mechanically, are provided, the mandrel being attached to the body and the bolster to the slider, or conversely, and means are provided for producing the relative displacement of the body and slider, so as to draw the head of the mandrel back toward the bolster.

In Fig. 1 the mandrel and bolster are shown ready to be inserted in a boiler-tube F which it is desired to fit in the tube-plate F, and in Fig. 2 they are shown inserted within the tube ready to commence operating. The head A of the mandrel is now forced back toward the bolster B, causing the bushing to be expanded in such a manner as not only to cause the tube end to expand into its bearing in the tube-plate, but also to flare or bellmouth the outermost portion of the tube if that extends, as shown in the figures, beyond the face of the tube-plate, as well as to pro+ duce at the back of the tube-plate a local circumferential enlargement of the tube. It is found inpractice that during the operation of expansion the forces within the apparatus act not only to effect such expansion, but also to hold the bolster stronglyagainst the work, thereby retaining the complete apparatus securely in position until the mandrel has completed its travel. Moreover, the'apparatus after it has produced a bell-mouth at a tube end automatically discharges itself from the work, provided that the portion of the mandrel behind the head is not of too great a length or that it is cased off or tapered back, as shown in the figures, for the outer end of the deformed bushing closing upon the end of the mandrel expels it. In Fig. 3 the apparatus and tube are shown aboutthe middlcof the process of expansion. In Fig. 4 the operation is virtually completed. Thecompleted joint is shown in Fig. 5. If it is not desired to hell the tube behind the tube-plate, butonly to expand the tube within the plates, it is obvious that this can be done by using a shorter bushing and commencing the operation with the shoulder A of the mandrel-head placed in a line, or nearly so, with the back surface of the tube-plate.

In some cases it is preferred to make the length of the bushing such that it protrudes slightly beyond the free end of the tube to be expanded in order that it may be forced in at the mouth of the tube, so as to shorten the bushing endwise and cause suflicient lateral expansion thereof to fill up any clearance which may exist between the bushing and the interior of the tube when the bushing is first inserted. This provision of the protruding end insures the thorough consolidation of the bushing before the mandrel commences its travel, for it is found that this consolidation of the plug by the thrust of the bolster on the outer end is effected with practical completeness before the mandrel exhibits any tendency to move within the tube toward the bolster. The deformable bushings may be made in one piece or in two or more segments. In the latter case they are more conveniently placed on the mandrel and come more readily out of the tube end after they have'been used and deformed. If it be desired to expand a portion of the tube other than an extreme end, the bolster is conveniently provided with an extension in the shape of a sleeve, into which the mandrel is drawn, the sleeve being entered to the desired extent into the tube before expansion is effected.

In Figs. 6, 7, S, and 0 is shown a conven-- ient form of apparatus to be worked by hydraulic or other fluid pressure. The shank A of the mandrel is secured to the head O of the pressure-cylinder. The head is screwed onto one end of the cylinder-body O, in the bottom of which is an opening 0 for the entry and exit of the motor fluid. The plunger D is provided with two or more studs or rods D, (three as shown in the figure,) which pass through holes in the head 0 and to which the bolster B is rigidlysecured-say by screws B.

It is evident that this construction may be reversed,the bolster being secured to or form ing the head of the cylinder, while the mandrel is secured to the piston, for example, by means of return-ties.

To control the admission of the motor fluid to and its exhaust from the prcssu re-cylinder, it is preferred to employ a duplex valve of the following construction: A valve-chest G, which may be formed with or fixed onto the end of the cylinder-body-say by screws, as shown in Fig. 8-is provided with a screwthreadcd hole G to receive the coupling II for the delivery-pipe and a second opening G also screw-threaded, to receive one end of a hollow spindle K, which forms the exhaust-passage for the pressure fluid. The outer end of this spindle is provided with a handle K or the like for its ready adjustment within the valve-chest, and its extreme outer end may be provided with a nozzle to receive an elastic pipe to carry off the exhaust-fluid. A port G corresponds with the opening C in the end of the cylinder-body. Between this port and the delivery-hole G is formed the seating G of a conical valve-face L of a valve L. The valve is provided with an extension upon which is a second'conical valve-face L adapted to seat itself on the inner end of the hollow spindle K. The valve is provided with a spring L which tends to hold the face L against its seat G and a fluid-tight plug G5 is provided for constructional and adjustment purposes. \Vhen now the parts are in the position shown in Fig. 8, the valve-face L, being on its seat, shuts off the pressure fluid from the port G and at the same time the end of the hollow spindle K is in contact with the face L and the exhaust-passage is therefore closed. By rotating. the spindle so as to force the valve back against the pressure of its spring and remove the valve-face L from its seat a clear passage is provided through the opening G and port G G into the cylinder, while the exhaust-passage is still held closed. By reversing the rotation of the spindle the valve-face L is brought back to its seat by the pressure of its spring and the delivery-passage shut off, and a further rotation of the spindle, removing the end of the same from the valve-face L, opens the exhaust-passage and allows the escape of the fluid from the cylinder.

In Fig. 10 is shown a convenient construction for operating the mandrel mechanically. The bolster B is rigidly secured to a body or frame M, within which are journaled two parallel screws M M on which is adjusted a slider or bridge N, carrying the mandrel. The screws are provided with wheels M M which engage with a common cog-wheel M operated by a ratchet or other convenient de vice worked either by hand or by an electric or other motel.

\Vhat I claim as my invention, and desire to secure by Letters Patent, is-

1. In an apparatus for expanding hollow bodies the combination with a bolster-piece having an aperture therethrough a headed mandrel, the shank of which works through said aperture, a deformable bushing, located between the mandrel-head and bolster, and means for moving the mandrel and bolster relatively to each other to deform the bushing; as and for the purpose set forth.

2. In an apparatus for expanding hollow bodies and in combination a bolster-piece havinga central aperture; a headed mandrel, the shank of which passes through said aperture; a deformable bushing placed between the mandrel-head and the bolster; a body to which the mandrel is attached; a slider to which the bolster-piece is attached, and means.

to alter the relative position of the body and the slider and deform the bushing substantially as specified.

3. In an apparatus for expanding hollow bodies and in combination a bolster-piece having a central aperture; a headed mandrel, the shank of which passes through said aperture; a deformable bushing placed between the mandrel-head and the bolster; a body to which the bolster-piece is attached; a slider to which the bolster is attached, and means to alter the relative position of the body and the slider and deform the bushing substantially as specified.

4:. In an apparatus for expanding hollow bodies and in combination a bolster-piece having a central aperture; a headed mandrel, the shank of which passes through said aperture; a deformable bushing placed between the mandrel-head and the bolster; a cylinder to which the mandrel is attached; a piston within the said cylinder and having studs extending beyond the cylinder-body, to which studs the bolster-piece is attached; and a valve-chest for admitting pressure fluid into and exhausting the same out of the cylinder substantially as specified.

5. In an apparatus such as described a mandrel having a beveled or curved shoulder be tween the shank and the head in combination with a bolster-piece provided with a central opening through which the shank of the mandrel works and formed with a shoulder for cooperating with the shoulder of the mandrel substantially as specified.

6. In an apparatus such as described, the combination with a bolster piece provided with a central opening, a mandrel having a shank working through said bolster-piece, the walls of the opening in the bolster-piece being tapered whereby the mandrel will have a working fit at but one point within the bol= ster; substantially as described.

'7. In an apparatus such as described, the combination with a fluid-pressure cylinder, of the headed mandrel, the shank of which is secured to the cylinder-head, a plunger working in said cylinder, the rods carried by said plunger passing through openings in the cylinder-head, the bolster secured to said rods, and mechanism for controlling the admission and exhaust of pressure to said cylinder; substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CHARLES VANDELEUR BURTON.

Witnesses:

HARRY B. BRIDGE, T. G. GLADWIN. 

